Heat applied transfers include a variety of indicia with inks, material layers, and adhesives that become bonded to material layers, for example, apparel such as shirts, jackets, or the like, upon pressurized contact and heating of the transfers and apparel between press platens. Graphic images and lettering may generally be accurately and quickly transferred to the apparel without bleeding or partial interruptions in the bonding of the transfer, as long as the presses can be operated at a predetermined temperature for a predetermined time and at a predetermined pressure.
The presses must be able to accommodate many variations in the arrangement of transfers and apparel, as well as the types of transfers and apparel materials available. Moreover, the presses accommodate a wide variety of temperatures, pressures, and time intervals associated with application of indicia to a garment. Due to the desire for flexibility and economic factors, presses have traditionally been manually operated, i.e., they often rely on a user (e.g., an operator) to control at least (a) the force applied through the platens and (b) the length of time the force is applied with a mechanical apparatus.
The accuracy and precision of the temperature, and the pressure and the time duration for which these parameters are applied to the transfers, are particularly important to complete an efficient bonding of the transfers to materials, and can be difficult to accomplish in an accurate and repeatable manner. In particular, and depending upon materials and the structure of the indicia to be applied to the apparel, indicia may be subject to inconsistent application conditions throughout the surface of apparel to which the transfer is applied. For example, the application of excessive pressure between the platen pressing surfaces may cause bleeding of the colors, while insufficient pressure may result in blotched or unattached areas where the indicia failed to adhere completely to the garment.
However, for some fabric types, such as lightweight polyester, tri-blend soft fabrics, and active sports fabrics, the materials are susceptible to searing, marking, fabric buckling, melting, scorching, puckering, wrinkling, and formation of ‘heat press boxes’ when the requisite heat is applied in the bonding process. Excess temperature is often a factor in all these issues. In addition to high temperature issues, marking commonly occurs around the edges of the platen and near buttons, zippers, and seams. Not only frustrating, an end product may also be unsellable and is therefore wasted product. One known solution to reduce or eliminate such effects includes pre-heating the fabric and other materials, but pre-heating adds time and cost and in one example even doubles the overall print time.
Accordingly, there is a need to improve the bonding process in heat presses, for materials that are susceptible to damage that can occur during high temperature operations.